Jin Sung-moon

Desperate to raise money for her younger sister's surgery, Hae-ran teams up with Tae-soo to kidnap her half-sister So-jin. So-jin wakes up confined in an unfamiliar place. Hae-ran and Tae-soo demand a hefty ransom, expecting her wealthy father to cough up the money. Upon discovering that one of her captors is her half-sister, So-jin enters a precarious alliance that blurs the lines between victim and perpetrator as she plots a counterattack against the ruthless Tae-soo.

Joo-young tries to call a friend on her birthday after a long time, only to find out that her number is not in use anymore. She spends all day to find her and learns some things she never knew about her lost friend up until now. Soon, the forgotten memory of that day comes back to her.